Perhaps you should try some spelling variations:
"lucha una investigacion" » "lucha la investigacion", "lucha e investigacion", "lucha ciencia investigacion", "lucha en investigacion", "hacha una investigacion", "luna una investigacion"
"lujan ma investigacion" » "lujan la investigacion", "lujan a investigacion", "lujan iap investigacion", "lucan ma investigacion", "lujan mora investigacion", "lujan de investigacion"
"juan de investigacion" » "juan la investigacion"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("lujan ma investigacion") or ("lucha una investigacion"))) or ("juan de investigacion"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("lujan ma investigacion") OR ("lucha una investigacion"))) OR ("juan de investigacion")).
• Removing quotes may allow a broader search: (((( lujan ma investigacion ) or ( lucha una investigacion ))) or ( juan de investigacion )).
• Adding a wildcard symbol may retrieve word variants: (((("lujan ma investigacion") or ("lucha una investigacion"))) or ("juan de investigacion"))*.